Conventionally, a driving apparatus for use in a wiper apparatus of a vehicle has been known and disclosed in Japanese Patent Application Laid-Open Publication No. 2011-234453. The driving apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2011-234453 comprises: a cylindrical yoke, a gear case to which the yoke is fixed, a cover for covering an opening of the gear case, and an electric motor disposed inside and over the yoke and the gear case. The electric motor comprises: a permanent magnet fixed to an inner surface of the yoke and an armature rotatably installed inside the yoke. The armature is formed by winding an energizing coil around it, and an armature shaft installed in the therein is rotated together with the armature. The armature shaft is disposed inside and over the yoke and the gear case. To the armature shaft, a commutator for energizing the coil is attached.
In the armature shaft, a worm is formed on an outer periphery of a portion disposed inside the gear case. A worm wheel is formed inside the gear case, and a gear formed on the outer periphery of the worm wheel is meshed with the worm. A terminal holder is formed in the gear case, and the terminal connected to the commutator is supported by the terminal holder. A positioning member is attached to the gear case, and the position of the armature shaft is determined in an axis direction by the positioning member.